The present invention relates to a fuel cell management system for an electronic device with a fuel cell installed and operates on a power supplied from the fuel cell, the system managing the power supply state of the fuel cell.
Fossil fuels have widely been used as energy sources for electric power production and automobiles. However, from the viewpoint of the problems of environmental disruption and fuel exhaustion, there is a growing demand for a clean inexhaustible energy source that substitutes for the fossil fuels.
Accordingly, the fuel cell has attracted increasing attention in recent years. It can be said that the fuel cell is a very clean cell since it can produce electrical energy through a chemical reaction of hydrogen with oxygen and discharges none of poisonous substances, greenhouse gases and the like. Therefore, researches and development of such the fuel cell have been actively carried out (refer to, for example, Japanese unexamined patent publication No. 2002-161997), and the fuel cell is expected to be applied to large-scale power plants, private power generations and automobile power sources.
Furthermore, size reduction of fuel cells has been promoted through the recent researches and development, and installation of fuel cells in domestic electrical appliances (electronic devices) and portable electronic devices is on the way to achievement. In the case where the conventional primary battery (cell) is used, the battery itself is required to be replaced when its residual quantity depletes, and it is impossible to partially replenish it. Therefore, in order to prevent battery rundown, the user is required to carry a lot of batteries. Moreover, the secondary battery (cell) requires recharging, a place with a charger and a power outlet and also much time for the recharging.
However, achieving the installation of a fuel cell enables the fuel cell to substitute for the conventional primary batteries represented by the alkaline battery and the manganese battery and the secondary batteries represented by the nickel-cadmium battery, the nickel metal-hydride battery and the lithium-ion battery. The energy density of the fuel cell can be expected to be several times that of the lithium-ion secondary battery, and the cell itself is not required to be replaced since it is only required to be replenished with a fuel from the outside even when the cell residual quantity runs out. Moreover, the fuel cell needs neither device nor place for charging dissimilarly to the secondary battery, and it is possible to immediately use the fuel cell upon fuel replenishment. Therefore, the user's convenience is remarkably improved.